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(NG Model.)

F. H.y LEFROY. GHANGBABLB GBARING.

No. 556,852. Patented Mar.. 24, 1896.

EJE

UNITED STATES PATENT FRANK I-I. LEFROY, OF NEV YORK, N. Y.

CHANGEABLE GEARING.

SPECIFICATION forming part of Letters Patent NoA 556,852, dated March24, 1896. Application nea my 2, 1895. sain No. 554,746. or@ modem .To@ZZ whom t may concern:

Be it known that I, FRANK H. LEFROY, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Changeable Gearing;and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to an improvement in gearing for crank-actuatedvehicles, and it is embodied in the construction and arrange ment ofmembers hereinafter .referred to and definitely pointed out in theclaims.

The invention is designed more particularly for application to bicyclesand tricycles, and is applicable to either the crank-shaft or the shaftof the driving-wheel.

Primarily the invention is designed to afford a very positive and easyvariation of the leverage and consequently the speed of thedriving-chain or other powentransmittin g instrumentality.

lVhile I have suggested that the invention is applicable to certainclasses of vehicles, I wish it understood that it may be applied toother classes of machinery with equally as good results.

IIeretofore it has been suggested to vary the speed of the driving meansor chain by shifting multiple gear of varying diameter, the gears beinginternal gears, and consequently limiting the number of variations tothe interior diameter of the smallest gear, and in such constructionsthe multiple gears are of necessity loosely mounted eccentrically, andare susceptible of disarrangement by the warping or bending oi' theirsupports, thereby throwing their teeth out of true alignment with themoving pinion. These, as well as other objections, can be urged againststructures employing internal multiple gears. It has also been suggestedin numerous cases to employ a shifting-gear, which may be employedeccentricallyas well as concentrically, but which provides for but onechange of speed. Such devices are, however, unsatisfactory, owing to thelimit of variation and to the general complicated arrangement of parts.`With my invention these objections are practically overcome` In thedrawings, wherein the preferred form of the invention is illustrated,and in which like letters of reference designate corresponding parts inthe several views, Figure l is a longitudinal vertical section takenthrough the crank-shaft and sleeve of a bicycle. Fig. 2 is an elevationlooking to the left hand of Fig. l and showing the shaft in section.Fig. 3 is a det-ail perspective of the shifting deviceA In the drawings,A designates the crank shaft, B the sleeve, and C the crank, all ofusual construction, with the exception that the shaft A hasalongitudinal spline l) thereon between the end of the sleeve and crank.

Slidingly supported on the shaft is the molto-gear D, the same beingprevented from independent rotation by having a groove cut in its inn erwall into which the spline passes. This gear D is composed of a steppedseries of disks d d d2, each having a diameter diftering from the other,arranged side by side and each being formed with external teeth, asshown. These gears constitute by preference an integral unit, but it isto be understood that they can be otherwise formed or constructedas, forinstance, the several steps of the gear can be made separately and thenbolted together. The inner wall of gear D is recessed and acircumferential groove d3 is formed in the edge wall of this recess, forpurposes presently to be explained.

E designates the sprocket-wheel, which is vin the form of a ring havingthe sprocketteeth on its outer periphery and a series of gear-teeth onits inner peripheral wall. The diameter of the interior of the ring issubstantially equal to the diameter of the part d of the gear, so thatthe latter will closely fit within the former, the teeth of therespective members intermeshing.

To independently support the sprocket-ring I form a groove in its innerside face and secure therein by a suitable locking-ring F thecarrying-frame G, consisting preferably of a ring having a iiangefitting in the recess. Suitable balls maybe interposed, if desired, toform an antiriction-bearing for the sprocketring on the frame. Thecarrying-frame is iiXedly held from rotation by being supported IOO'sleeve B.

on suitable arms g g' projecting outward from a sliding frame H andconnected with the carrying-frame G at its bottom an d sides only, sothat the upward movement of the-ring is unopposed by the arms.

The sliding frame II comprises the two curved side bars 7i ZL curved ona radiiwith its center the center of the rear axle to prevent thebinding of the chain by the adjustments. These side bars are connectedat their topsand bottoms by the web h2 and the crossbar '2.3.

K designates the supporting-plate keyedor otherwise flxedly secured onthe end of the This plate is fashioned to conform to the shape of theframe H, but is somewhat smaller, its side edges being fitted in groovesh4 formed in a flange h5 on the side bars only of the frame H. By thismeans it will be apparent that the frame H will have or be permitted asubstantially vertical movement on the supporting-plate or at aboutright angles to the shaft, and by its movement the sprocket* ring willbe raised or lowered, as the case may be.

The flanges Zr" on the bars ZL Zt" project laterally beyond thecross-bar and web, so that the frame H is permitted a movement whichkwill carry its opposite ends beyond the platel K, the limit of movementbeing governed by the distance between the cross-bar and web, which, aswill be readily understood, can be greatly varied without necessitatingstructural changes in the machine-frame.

To effect the relative adjustment of the sprocket ring and gear I employwhat I term an adjuster or cam L, which consists of a flat plate Zhaving a circular aperture therein,

and sleeve the same loosely on the hub Zo of the liXed plate K, the samebeing properly.

held in place by a suitable nut. The plate Z has an arm oractuating-lever L thereon, which extends upward to any convenient pointand by which the same may be shifted or rotated about its axis. In thelower and side portions of the plate Z is formed a campath Z fashionedto correspond to the required vertieal movement of the sprocketring.Into this cam path or groove Z is extended a pin fm made fast to the webZi of the plate I-I, so that as the plate Z is rotated the plate H willbe raised or lowered through the medium of the pin, the pin working in aslot k3 in the plate K.

To provide for the movement of the gear D, I form a squared hollowbushing Zt' on the plate K, and through this bushing pass a link Msquared in cross-section and having a hook o at its outer end whichloosely engages in the groove Z3 of the gear D. The opposite end of thelink is turned down or hooked, as at o', and passes into a cam-groove Z2formed in a circular-shaped flange concentrically mounted or formed onthe side of the plate Z of the adjuster L.

By reference to the drawings it will be noted kat right angles to theother.

one serves to elevate the pin therein the other.

being horizontal, will serve to move the link These cam1 grooves are soshaped that the movement or' the ,parts will be properly timed, and whenneeded the movement of the gear will be stopped and both movementsinterrupted or locked by interrupted pitches in the cams.

It will be noted that the shifting device and the supporting-frame H areboth arranged inwardly beyond the gear and are therefore located in aposition to prevent accidental interference, and at the same time may bereadily applied to the usual structure vwithout materially altering theparts.

In operation, by shifting the lever L' the gear is moved longitudinally,and as its sue ceeding step reaches the plane of the sprocket-rin g thelatter is lowered onto the gear and the speed thereby varied, themovement be- .ing simple and eective. By forming the bushing on theplate K the link M is held in its horizontal position, so that it isprevented from being cramped orbound in the groove (Z3.

"While I have shown what I deem the preferable form of construction Iwish it understood that other forms may be employed so long as theprinciple of the external gear is retained, which feature I regard as ofmuch importance. I have shown but a three-stepped gear for convenience,but it will be evident that any desired number may beused, ranging fromtwo to ten or twenty. The gear being supported directly on the axle isheld positively irrespective of weight or number.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

l. In a gearing for crank actuated machines, the combination with acrank-shaft and a sleeve, of an externally-toothed muitogear looselymounted on the shaft and comprisinga series of gears of varyingdiameters. means for preventing an independent rotary movement of thegear, a vertically-adj ustable power-transmitter ring having a toothedinner wall, an adjustable frame supporting the ring, a fixed supportwith which the frame slidingly engages, and shifting means for changingthe relative position of the gear and sprocket, substantially asdescribed.

2. In a changeable gear for crank-actuated machines, the combinationwith a shaft, of a stepped multe-gear sleeved directly on the shaft andformed with external teeth, means for preventing an independent rotationof the shaft and gear, a power-transmitting ring with which the gearengages, means for shift` ing the ring at substantiallya right angle tothe gear, and means for changing the relative lateral position betweenthe gear and ring, substantially as described.

3. In a changeable gear for crank-actuated machines, the combinationwith a crank-shaft and its sleeve, of a longitudinally-movable IIOmuito-gear sleeved on the shaft having` eX- ternal teeth, means forpreventing independent rotation oi' the gear and shaft, a plate fixed onthe sleeve, a curved carrying-frame slidinglysupported on the plate,arms on the frame, a power-transmitting ring arranged to engage with thegear, loose connection between the ring and arms, a shifting cam mountedon the sleeve having a plurality of cam-paths therein, a slidingconnection between the cam and carrying-frame, and a sliding connectionbetween the cams and gear, substantially as described.

et. In a changeable gear for crank-actuated machines, the combinationwith a crank-shaft and its sleeve, of an externally-toothed muitogear onthe shaft, a power-transmitting ring arranged to engage the gear, acurved carrying-frame for the ring comprising two side bars, andlaterally extending supportingarms, a plate xed to the sleeve and withwhich the frame sli din gly engages, and a shifting device mounted onthe sleeve inwardly beyond the plate for changing the relative positionof the ring and gear, substantially as described.

In a changeable gear for crank-actuated machines, the combination With acrank-shaft and its sleeve, of an externally-toothed multogear,slidingly supported on the shaft, means for preventing independentrotation of the gear and shaft, a sprocket-ring independent of the gear,having internal teeth arranged to engage the gear, a carrying-framelocated inwardly beyond the gear, arms extending outward from the frameand having a journal connection with the ring, a xed support for theframe with Which the latter has a sliding connection, and a shiftingdevice having connections With the frame and gear and loosely sleeved onthe frame, substantially as described.

G. In a chan gea-blc gear for crank-actuated machines, the combinationwith a crank-shaft and its sleeve, of a multe-gear on the shaft, apower-transmitting ring arranged to engage the gea1,means for adjustablysupporting the ring directly on the sleeve, a rotatable shiftingl devicehaving horizontal and verticalcam-grooves therein and connectionsengaging in the grooves for changing the relative positions of the gearand ring, substantially as described.

7. In a changeable gear for crank-actuated machines, the combinationwith a shaft, of a muito-gear on the shaft, a sprocket-ring independentof the gear, a ring supporting the sprocket-ring loosely engagingtherewith, a curved carrying-frame for the supportingring located inwardfrom the ring, arms connecting the carrying-frame and supportingring, afixed support for the carrying-frame a cam-plate having loose connectionwith the carrying-frame and gear, and comprising a horizontal plate anda vertical plate having cams thereon, and a lever for shifting theplates, and means operated by the cams for shifting the gears and ring,substantially as described.

8. In a changeable gear for crank-actuated machines, the combinationWith a shaft, of an external toothed multe-gear loosely mounted to movelongitudinally on the shaft, a poiver-transmiting ring arranged to beengaged With the gear and movable in a vertical plane only, and meansJfor changing the relative position of the ring and gear, so that thering will be caused to engage the dierent steps or sections of the gear,substantially as described.

In testimony whereof I aiiix my signature in presence of two Witnesses.

FRANK II. LEFROY.

Witnesses G. A. PENNINGTON, L. S. BACON.

